Reliability of preoperative MRI findings in patients with lumbar spinal stenosis

Background Magnetic Resonance Imaging (MRI) is an important tool in preoperative evaluation of patients with lumbar spinal stenosis (LSS). Reported reliability of various MRI findings in LSS varies from fair to excellent. There are inconsistencies in the evaluated parameters and the methodology of the studies. The purpose of this study was to evaluate the reliability of the preoperative MRI findings in patients with LSS between musculoskeletal radiologists and orthopaedic spine surgeons, using established evaluation methods and imaging data from a prospective trial. Methods Consecutive lumbar MRI examinations of candidates for surgical treatment of LSS from the Norwegian Spinal Stenosis and Degenerative Spondylolisthesis (NORDSTEN) study were independently evaluated by two musculoskeletal radiologists and two orthopaedic spine surgeons. The observers had a range of experience between six and 13 years and rated five categorical parameters (foraminal and central canal stenosis, facet joint osteoarthritis, redundant nerve roots and intraspinal synovial cysts) and one continuous parameter (dural sac cross-sectional area). All parameters were re-rated after 6 weeks by all the observers. Inter- and intraobserver agreement was assessed by Gwet’s agreement coefficient (AC1) for categorical parameters and Intraclass Correlation Coefficient (ICC) for the dural sac cross-sectional area. Results MRI examinations of 102 patients (mean age 66 ± 8 years, 53 men) were evaluated. The overall interobserver agreement was substantial or almost perfect for all categorical parameters (AC1 range 0.67 to 0.98), except for facet joint osteoarthritis, where the agreement was moderate (AC1 0.39). For the dural sac cross-sectional area, the overall interobserver agreement was good or excellent (ICC range 0.86 to 0.96). The intraobserver agreement was substantial or almost perfect/ excellent for all parameters (AC1 range 0.63 to 1.0 and ICC range 0.93 to 1.0). Conclusions There is high inter- and intraobserver agreement between radiologists and spine surgeons for preoperative MRI findings of LSS. However, the interobserver agreement is not optimal for evaluation of facet joint osteoarthritis. Trial registration www.ClinicalTrials.gov identifier: NCT02007083, registered December 2013.

Ultrasound Measurements of the Median Nerve at the Distal Wrist Crease Correlate With Electrodiagnostic Studies

Background: Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy and is commonly evaluated using electrodiagnostic studies (EDSs). Ultrasound (US) has emerged as a potentially easier and more comfortable alternative to EDSs. The purpose of this study is to evaluate whether measurements of the cross-sectional area (CSA) of the median nerve via US correlate with the severity rating of CTS based on EDSs. Methods: A retrospective review of patients aged 18 years or older who underwent US and EDSs of the median nerve for CTS was performed. Sensory nerve action potential, distal motor latency, and compound muscle action potential were measured, and severity was graded on American Association of Neuromuscular and Electrodiagnostic Medicine guidelines. Cross-sectional area of the median nerve was measured via US at the wrist crease. Results: There was a significant association between increasing CSA and increasing EDS severity ( P < .0001). The mean CSA for normal, mild, moderate, and severe CTS was 7.48 ± 2.00, 10.36 ± 2.53, 12.01 ± 3.64, and 14.34 ± 4.77 mm2, respectively. The area under the curve demonstrated the ability of median nerve CSA to discriminate between normal and abnormal EDSs with an optimal cutoff CSA of ≥10 mm2, as well as, the ability to discriminate between mild CTS and moderate to severe CTS at a cutoff CSA of greater than or equal to 12 mm2. Conclusions: The results of this study show that US measurements of the median nerve at the distal wrist crease discriminate between normal and abnormal EDSs, and between mild CTS and moderate to severe CTS.

Effectiveness of lumbar stabilization exercise with real-time ultrasound imaging biofeedback on lumbar multifidus muscle cross-sectional area in individuals with non-specific chronic low back pain: a study protocol for a randomized controlled trial

Background Structural impairment of the lumbar multifidus muscle, such as reduced cross-sectional area, is evident among individuals with chronic low back pain. Real-time ultrasound imaging (RUSI) biofeedback has been reported to improve preferential activation of as well as retention in the ability to activate the lumbar multifidus muscle during lumbar stabilization exercises (LSE). However, evidence of the effectiveness of this treatment approach in individuals with non-specific chronic low back pain (NCLBP) is still limited. The purpose of this study is, therefore, to determine the effectiveness of LSE with RUSI biofeedback on lumbar multifidus muscle cross-sectional area in individuals with NCLBP. Methods/Design This study is a prospective, single-center, assessor-blind, three-arm, parallel randomized controlled trial to be conducted at National Orthopedic Hospital, Kano State, Nigeria. Ninety individuals with NCLBP will be randomized in a 1:1:1: ratio to receive LSE, LSE with RUSI biofeedback, or minimal intervention. All participants will receive treatment twice weekly for 8 weeks. The primary outcome will be the lumbar multifidus muscle cross-sectional area. The secondary outcomes will include pain (Numerical Pain Rating Scale), functional disability (Roland–Morris Disability Questionnaire), and quality of life (12-Item Short-Form Health Survey). All outcomes will be assessed at baseline, 8 weeks post-intervention, and 3 months follow-up. Discussion To our knowledge, this study will be the first powered randomized controlled trial to compare the effectiveness of LSE training with and without RUSI biofeedback in individuals with NCLBP. The outcome of the study may provide evidence for the effectiveness of LSE with RUSI biofeedback on enhancing the recovery of the lumbar multifidus muscle in individuals with NCLBP. Trial registration Pan African Clinical Trials Registry (PACTR201801002980602). Registered on January 16, 2018.

Morphological and Functional Characteristics of the Peroneus Muscles in Patients with Lateral Ankle Sprain: An Ultrasound-Based Study

Background and Objectives: The effectiveness of multiple ultrasound evaluations of the peroneus muscles morphology, including muscle cross-sectional area (CSA) and connective tissue, after lateral ankle sprain (LAS) is unknown. This study aimed to measure the peroneus muscles after LAS at three points, adding distal 75% to the conventional measurement points, in order to obtain a detailed understanding of the post-injury morphology and to propose a new evaluation index of the peroneus muscles for multiple LAS. Materials and Methods: Participants with and without LAS (LAS and control groups, 16 each) were recruited. The muscle cross-sectional area (CSA) and muscle echogenicity were measured using a B-mode ultrasound system at 25%, 50%, and 75% proximal to the line connecting the fibular head to the lateral malleolus. The ankle evertor strength was measured using a handheld dynamometer. Simultaneously, the peroneus longus (PL) and peroneus brevis (PB) muscle activities were measured using surface electromyography. Measurements for the LAS side, non-LAS side, and control leg were performed separately. Results: The CSA was significantly higher at 75% on the LAS side than on the non-LAS side and in the control leg. Muscle echogenicity of the LAS side at 75% was significantly lower than that of the non-LAS side and the control leg. Muscle activity of the PL was significantly lower and the PB was higher on the LAS side than on the non-LAS side and in the control leg. Conclusions: The PL was less active than the PB, while the PB was found to be overactive, suggesting that PB hypertrophy occurs due to an increase in the percentage of muscle fibers and a decrease in the connective tissue. Therefore, it is necessary to evaluate the condition of the PL and PB separately after LAS.

Cervical Spinal Cord Atrophy can be Accurately Quantified Using Head Images

Background Spinal cord atrophy provides a clinically relevant metric for monitoring MS. However, the spinal cord is imaged far less frequently than brain due to artefacts and acquisition time, whereas MRI of the brain is routinely performed. Objective To validate spinal cord cross-sectional area measurements from routine 3DT1 whole-brain MRI versus those from dedicated cord MRI in healthy controls and people with MS. Methods We calculated cross-sectional area at C1 and C2/3 using T2*-weighted spinal cord images and 3DT1 brain images, for 28 healthy controls and 73 people with MS. Correlations for both groups were assessed between: (1) C1 and C2/3 using cord images; (2) C1 from brain and C1 from cord; and (3) C1 from brain and C2/3 from cord. Results and Conclusion C1 and C2/3 from cord were strongly correlated in controls ( r = 0.94, p<0.0001) and MS ( r = 0.85, p<0.0001). There was strong agreement between C1 from brain and C2/3 from cord in controls ( r = 0.84, p<0.0001) and MS ( r = 0.81, p<0.0001). This supports the use of C1 cross-sectional area calculated from brain imaging as a surrogate for the traditional C2/3 cross-sectional area measure for spinal cord atrophy.